It all began when Calden Carroll was a graduate student at the University of Oregon, he worked in the lab of UO chemists Mike Haley and Darren Johnson, who were studying ways to tune the optical properties of molecules to respond to specific species of interest. For example, they had discovered a way to “turn on” a class of compounds when chloride was present, causing them to light up with a green, fluorescent light.

As part of his PhD project, Carroll was working with Haley and Johnson to create a molecular probe to visualize the movement of chloride through cells and other complex media. Instead of activating the chloride like they planned, their experiment caused the nitrate to light up—a big failure for their project.

What Johnson describes as a “very bad day” in the lab could have been the end of the story, but the accidental discovery led to the foundation of a new startup company, SupraSensor. It turns out that visualizing the movement of nitrate was not useless—far from it—and was the potential solution to a $2.4 billion problem facing farmers.